Collision mitigation sucks. Is dangerous and brings down mpg.

neal adkins

neal adkins

Active Member
Something i have noticed that will also hurt the mpg is the collision mitigation doing moderate braking when i'm 200 ft behind a slower moving vehicle. Then when i change lanes it rapidly accerates to reach the set speed. It does this even when set to follow the closest. This is not very smart. I wish i could set my cms to only be active when an emminent collision is detected. I really takes away from the cars efficency in traffic. Also can be dangerous when it brakes unexpectedly when i am cutting into traffic. This system gets a thumbs down from me.
 
Yesterday the car driving in front of us, at 25 mph, decided to pull over to the curb and park. Our Clarity braked hard, coming to a complete stop, for no good reason. Fortunately the car in back of us didn't hit us.

Collision mitigation is a good feature but not as currently implemented by Honda. This hard breaking when not necessary happens all too often.
 
I've just learned to anticipate it and steer away from whatever it doesn't like. It doesn't take much of a tweak on the steering either.

Also, this sounds counter-intuitive but set it to have the highest sensitivity, as in it will kick in sooner than later. What that does for me is it will beep to brake with no braking yet and with enough ample warning that I just steer a little to the other side of whatever is causing it to trigger and it then is happy and doesn't do any more.
 
jdonalds said:
Yesterday the car driving in front of us, at 25 mph, decided to pull over to the curb and park. Our Clarity braked hard, coming to a complete stop, for no good reason. Fortunately the car in back of us didn't hit us. You can turn the system off but have to do it every time you turn on the car. They just need a setting for only when imminent collision detected.

Collision mitigation is a good feature but not as currently implemented by Honda. This hard breaking when not necessary happens all too often.
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weave said:
I've just learned to anticipate it and steer away from whatever it doesn't like. It doesn't take much of a tweak on the steering either.

Also, this sounds counter-intuitive but set it to have the highest sensitivity, as in it will kick in sooner than later. What that does for me is it will beep to brake with no braking yet and with enough ample warning that I just steer a little to the other side of whatever is causing it to trigger and it then is happy and doesn't do any more.
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I have also adapted to preempt the system to prevent unessacary braking most of the time. But i think the system will eventually cause an accident and Honda will be found liable. I like the car but the cms is not going to work out in the long run. It can cause some one to rear end me when braking unexpectedly.
 
To each his own.
You can turn it off if you don’t want it, but you have to to that at every start.

I don’t have a problem wirh the CMBS in town. It has given me only 2 false signals in 6 months (alert, no braking) and so far has only beeped and illuminated the brake indicator, usually when the car in front is making a turn and I close the gap anticipating their turn.
In town it’s doing a great job of not alerting to cars in oncoming lanes on turns. I too, like @weave, have it set to most sensitive/longer distance and have not had it brake for me yet.
 
KentuckyKen said:
To each his own.
You can turn it off if you don’t want it, but you have to to that at every start.

I don’t have a problem wirh the CMBS in town. It has given me only 2 false signals in 6 months (alert, no braking) and so far has only beeped and illuminated the brake indicator, usually when the car in front is making a turn and I close the gap anticipating their turn.
In town it’s doing a great job of not alerting to cars in oncoming lanes on turns. I too, like @weave, have it set to most sensitive/longer distance and have not had it brake for me yet.
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I would agree that in town i have had very few problems. My problem has been mostly on freeway driving. My scary experience was when i was timing a lane change from right lane to left attempting to pass. When i got close to the slow moving vehicle and started switching lanes, my car brakes moderately. But there was a car in the left lane a little behind me. So it scary when the car unexpectedly braked with a car that close in the other lane. I know it is a little confusing to understand. So in town i will leave on. But on freeway or high speed driving turn it off. Drivers beware.
 
Are we talking about adaptive cruise control (ACC) or collision mitigation (CMBS)? I think the original poster mentioned CMBS was but really talking about ACC. I've only had the collision mitigation flash the brake signal a few times when it mistook pavement markings for objects, but the brakes were never applied. ACC, on the other hand, seems to have a problem when a car that is followed changes lanes and stops, such as when the car pulls to the side to make a turn. Otherwise, I have found the ACC to behave exactly as I would expect. ACC slowing down is as expected, but speeding up is a bit sluggish. However, I just hit the gas to bring the car up to speed a little faster. ACC should always be disabled when the car starts, so if it's causing a problem, then it must have been explicitly enabled.
 
ClarityDoc said:
Have you tried Sport mode with ACC to mitigate this? I find it does help, but I'm fine with being sluggish so I tend to stay in Eco mode.
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You can also get faster resume speed by pushing Econ button to take Econ off and then reinstate it with one push after catching up.
 
When the car is designed for maximum efficiency not power i personally perfer slower and more efficient acceleration to the set speed.after braking.
 
Like I said in the other thread, this is a mismatch between a driver expectation and the technology limitations.

You complain about the car starting to slow down 200 ft away on a freeway with ACC so if you expect the car to cut to the other lane and continue the same speed, you need a Tesla and pay extra for that feature. Otherwise there will be more people complaining about the car not stopping or braking harder than it should.

I too suffer from all the braking cause by the car in front changing lanes, but on the other hand I am glad it does because that is exactly what ACC should do if there is a curve in front and the car in front is making the turn and my car is following instead of going full speed at the curve like it does now when there is no car in front.
 
A
Odobo said:
Like I said in the other thread, this is a mismatch between a driver expectation and the technology limitations.

You complain about the car starting to slow down 200 ft away on a freeway with ACC so if you expect the car to cut to the other lane and continue the same speed, you need a Tesla and pay extra for that feature. Otherwise there will be more people complaining about the car not stopping or braking harder than it should.

I too suffer from all the braking cause by the car in front changing lanes, but on the other hand I am glad it does because that is exactly what ACC should do if there is a curve in front and the car in front is making the turn and my car is following instead of going full speed at the curve like it does now when there is no car in front.
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Actually my comment was about abrubt moderate braking at about 200 ft from slower vehicle, then when i change lanes it moderately accelerates to regain set speed. That part should be improved.
The complaint was about lane changing to pass then the car unexpectedly brakes in the process. This is potentially dangerous when i am pressing the accelerator and the over rides me and applys the brake as i am merging in front if another vehicle. But I am learning to adjust to the car. It should have an option to only mitigate imminent collision imho.
 
GTO 409 said:
I thought the recs above were for the CMS to be at the highest, longest setting, not the shortest!
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Im not sure. But im just tired of the cms/ acc over reacting with unnessacary braking. So i want it to give me more time to change lanes without slowing down. If i continue to have trouble i will just turn it off when driving in freeway traffic.
 
Odobo said:
You complain about the car starting to slow down 200 ft away on a freeway with ACC so if you expect the car to cut to the other lane and continue the same speed, you need a Tesla and pay extra for that feature.
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Sorry, but even Tesla's cars in their current state of Autopilot+AutoSteer never, ever change lanes without the driver telling them to. Not even to avoid an accident.

* * * * *

The overall tone of this thread, claiming that ABS will "cause" an accident, is to me an indication that people don't understand how self-driving cars are being developed. The aim of autonomous driving systems isn't to slavishly copy human driving behavior; it's to develop an autonomous driving system which is considerably safer than the average human driver. This absolutely demands that autonomous cars will sometimes "behave" differently than human drivers. If they behaved exactly the same, then they would have just as many accidents!

Perhaps there needs to be some sort of warning light pattern on cars that are under the control of an autonomous or semi-autonomous driving system, to warn human drivers that such cars may react in unexpected ways. But we can't expect those developing autonomous driving systems to make the cars act exactly like human drivers and to be considerably safer drivers. Those are mutually contradictory goals, and it's simply impossible to achieve both.

Human drivers are going to have to get used to how autonomous cars behave. Humans are flexible and can easily "reprogram" themselves, changing their behavior to fit the circumstances. Machines... not so much. That's not to say that autonomous driving system designers shouldn't make any effort to mitigate the vehicle's tendency to make sudden unexpected moves, but the primary goal has to be safe driving, not trying to mimic the exact behavior of human drivers.

All just my opinion, of course.
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What im talking about is apparently too simple for you and the Honda engineers. Unexpected moderate braking invites accidents, especially rear end collision.
 
neal adkins said:
What im talking about is apparently too simple for you and the Honda engineers. Unexpected moderate braking invites accidents, especially rear end collision.
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It only "invites" rear end collisions if you're following the car in front of you too closely, which sadly is an all too common habit among human drivers. Autonomous or even semi-autonomous vehicles should be programmed to maintain a safe following distance.

To a large extent, autonomous cars will achieve a lower accident rate merely by following the safe driving procedures which human drivers should practice, but get into the habit of not doing.

For example, in Drivers' Ed in school, we were taught to maintain a two-second following distance from the car ahead. But in practice in heavy traffic on a multi-lane road, this is literally impossible. I've tried. If you try to maintain more than about a 1.5 second following distance, you leave a gap between you and the car in front that's so wide that cars from the adjacent lane will cut in front of you. And not just occasionally, but continuously; car after car after car. In practice I've found that about a 1.5 second following distance is the best you can hope for, and even then some (human) drivers will still cut over in front of you.

Presumably, autonomous cars will be programmed to actually use the 2-second following distance rule.
 
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